St. Nicholas Cabasilas: on the reality of our adoption as sons of God

 This is the reality of our adoption as sons of God. Unlike human adoptions, it does not consist in the mere name, nor does it confer honor merely to the extent that those who have been adopted share the name of those who have been naturally born and have the same father as they, without having undergone the same birth and its pangs. In this case, however, there is a real birth and a sharing with the only-begotten Son not of the surname only, but of His very Being, His Blood, His Body, His Life. What, then, is greater than that the Father of the only-begotten Son Himself recognizes in us His members and finds the very form of the Son in our faces? It says, "He predestined them to be conformed to the image of His Son" (Rom 8:29).

+St. Nicholas Cabasilas, from The Life in Christ, book 4, #9. How the Eucharist makes us sons of God.

St. Nicholas Cabasilas: The fruits of the Sacraments

 We depart from this water [of Baptism] without sin. Because of the Chrism we partake of His graces, and because of the banquet [of the Holy Eucharist] we live with the same life as He does. in the world to come we shall be gods with God, fellow-heirs with Him of the same riches, reigning with Him in the same kingdom - that is, unless we of our own free will bling ourselves in this life and rend asunder the royal garment. This alone we contribute to the life - that we submit to His gifts, retain His grace, and do not reject the crown which God by many toils and labors has prepared for us.

+St. Nicholas Cabasilas, from The Life in Christ, book 1, #11.

St. Nicholas Cabasilas: On God's destiny for mankind

 That humans should become gods and sons of God, that human nature should be honored with God's honor, that our clay should be raised to such a height of glory as to be equal in honor with the divine nature, equal to God... This is God's virtue which has covered the heavens.

+St. Nicholas Cabasilas, from On the Life in Christ, 1

St. Nicholas Cabasilas: Life in Christ in this world

In this present world... it is possible for the saints not only to be disposed and prepared for that life [in Christ] but also even now to live and act in accordance with it. Paul writes, "lay hold on eternal life" (1 Tim 6:12), and "it is no longer I who live, but Christ who lives in me" (Gal 2:20). The divine Ignatius says, "there is water living and speaking in me" (Epistle to the Romans 7:2). Scripture is full of such passages! Beside all these, when He who is the Life promises the saints to be with them forever, and says, "Behold, I am with you always, to the close of the age" (Matt 28:20), what else should one think? When He had sown the seed of life on the earth (Luke 8:5) and cast on it the fire (Luke 12:49) and the sword (Matt 10:34), He did not forthwith depart and leave it to men to plant and nourish the seed and to kindle the fire and use the sword. He Himself is truly with us and "works in us to will and to do" (Phil 2:12), as the blessed Paul said. It is He Himself who kindles and applies the fire, He Himself holds the sword. In short, "neither does the axe boast without him who lifts it" (Is 10:15). Those from whom the Good One is absent will attain to no good.
Yet the Lord did not promise merely to be present with the saints, but to abide with them - nay more than this, to make His abode in them (John 14:23). What then shall I say? Where it is said that He is united with them, it is with such love that He becomes one spirit with them. As Paul says, "he who is united to the Lord becomes one spirit with Him" (1 Cor 6:17), and "that you may be one body and one spirit, just as you were called" (Eph 4:4).
+St. Nicholas Cabasilas, from The Life in Christ, book 1, #2: The life in Christ consist of union with Him.

St. Nicholas Cabasilas: How great are the Mysteries!

O how great are the Mysteries [i.e., the Sacraments]! What a thing it is for Christ's mind to be mingled with ours, our will to be blended with His, our body with His Body and our blood with His Blood! What is our mind when the divine mind obtains control? What is our will when that blessed will has overcome it? What is our dust when it has been overpowered by His fire?
That these things are so Paul shows when he claims that he has neither his own mind nor will nor life, but that all these have become Christ's for him. He states, "we have the mind of Christ" (2 Cor 2:16), and "you desire proof that Christ is speaking in me" (2 Cor 13:3), and "I yearn for you all with the affection of Christ Jesus" (Phil 1:18). From this it is clear that he has the same will as Christ. To sum it all up, "it is no longer I who live, but Christ lives in me" (Gal 2:20).
+ St. Nicholas Cabasilas, from The Life in Christ, fourth book, #2